Last week, a 45-year-old Serbian lawyer named Dragan Antic fled his home in southern Kosovo for fear of ethnic Albanian guerrillas who were beginning to pour into town. Today, he stood in the center of Belgrade, denouncing Yugoslav President Slobodan Milosevic as the source of his troubles.

"It is Slobodan who is guilty," he shouted, as police attempted to break up a protest rally by 100 or so Serbs who fled Kosovo. "What was the purpose of fighting this war if we had to give Kosovo away? Before the war, we were living in our own homes; now we have nothing more than the clothes you see on our backs."

"Milosevic led us in the wrong direction," complained another displaced Serb, Stojan Stojanovic, who had run a small travel agency in the Kosovo town of Prizren. "We should be entering the European Union and cooperating with the rest of the world; instead, we are completely isolated."

For the past two days, Serbs newly arrived here have been demonstrating as much anger at Milosevic for abandoning them to their fate as at NATO for the 78-day bombing campaign that led to establishment of an international protectorate in Kosovo, a province of Serbia, Yugoslavia's dominant republic.

Although the demonstrations have been small in scale and were quickly broken up by police, they could be a harbinger of trouble for a leader who owed his rise to power to promises that he would defend the interests of Kosovo's Serbian minority.

Adding to the pressure on Milosevic, a pro-Western political opposition group announced plans today for a series of demonstrations to demand early parliamentary elections in Serbia and a relaxation of government control of the news media.

Vladan Batic, coordinator of Alliance for Change, said the first demonstrations will take place Saturday in the central Serbian towns of Kraljevo and Cacak, both of which are controlled by the opposition.

Aware of the potential for civil disorder inherent in the presence of large numbers of disgruntled people, authorities have played down the exodus of Serbian civilians from Kosovo and sought to persuade those who left to return.

Police have done their utmost to prevent Kosovo Serbs from reaching Belgrade -- capital of both Yugoslavia and Serbia -- by erecting barricades on the main road from Kosovo and encouraging displaced persons to report to reception centers in provincial towns.

"They tried to block us from coming to Belgrade, but we managed to escape from the reception centers," said Prokopija Mojisevic, who got a lift in a car bearing government license plates. Others finessed their way through the police checkpoints by saying they were going to Belgrade to stay with relatives.

The influx of Kosovo Serbs into Belgrade has been relatively small compared to the chaotic scenes four years ago when a quarter-million Croatian Serbs fled here after the Croatian army reasserted control over a region that had become an autonomous enclave run by Belgrade-backed nationalist Serbs.

But the fate of the Kosovo Serbs is a much more emotional issue for the inhabitants of Serbia proper than the fate of the Croatian Serbs. Even though Croatia had been part of the old six-republic Yugoslav federation, it was viewed as a foreign state by most Serbs; Kosovo, by contrast, is seen as an integral part of Serbia and the cradle of Serbian civilization.

"The situation is very fragile," said Dusan Masic, editor of the now silent independent radio station B-92, as he watched the Kosovo Serbs gather in central Belgrade. "Every week, there is likely to be some new test for the regime, and it will be difficult for Milosevic to keep it all together."

All street demonstrations have been banned under state-of-war regulations introduced on March 24, after NATO launched its aerial bombardment of Yugoslavia to force Milosevic to agree to a U.S.-inspired peace plan for Kosovo. The government called on the Yugoslav parliament today to lift the regulations, perhaps as early as this weekend, but appears likely to retain at least some emergency powers to forestall mass protests.

Although police detained the leader of today's demonstration, Svetozar Fisic, they seemed eager to defuse the protest without violence. Some officers showed sympathy for the demonstrators. "Don't blame us," one policeman pleaded with the protesters. "We were sent to Kosovo ourselves and did our best to ensure your security."

By some estimates, up to 50,000 Serbs have left Kosovo over the past two weeks in the wake of retreating Yugoslav troops and Serbian police. Serbs who stayed behind have complained that NATO peacekeepers have failed to provide them with adequate protection from violence and intimidation by ethnic Albanian separatist guerrillas and civilians seeking revenge for the horrors inflicted on them over the past 2 1/2 months.

Until this weekend, the exodus of Serbs from Kosovo was a taboo subject for official news media here. Then the propaganda line changed, and authorities suddenly began urging Serbs who had fled Kosovo to return to their homes. On Saturday evening, Serbian Deputy Prime Minister Milovan Bojic went on television to assure Kosovo Serbs that their security was guaranteed by "United Nations forces." Serbian journalists are under strict orders to avoid use of the phrase "NATO troops" in connection with the Kosovo peacekeeping operation.

As part of the new propaganda campaign, state-run television has been broadcasting positive reports on the activities of Western peacekeeping troops in the province, showing them disarming Kosovo Liberation Army guerrillas and patrolling the streets of Pristina, the Kosovo capital, and other towns. Just a few weeks ago, the official news media were denouncing the same troops as "NATO aggressors" and insisting they would never be permitted to set foot in Kosovo.

Tonight, state television aired film of convoys of Serbian civilians returning to Kosovo from "temporary" camps in southern Serbia. The announcer told viewers that conditions in the province were rapidly returning to normal and that "all those who left will return."